Lessons learnt from implementation of NANO modified emulsion technology on street rehabilitation on a recent SANRAL funded community development project

Abstract

The SANRAL funded research on unconventional soil stabilisers identified Nano Modified Emulsion (NME) as effective and viable natural soil and gravel stabilisation options. The inclusion of NME in the new Draft (2022/23) TRH 24 established NME technology as cost saving option to upgrade low traffic volume gravel roads to surfaced standards. NME treated material makes natural or marginal quality granular materials water proof and flexible versus the negatives of cracking and potential crushing of cement treated material. A Community Development Project (CDP), linked to the current SANRAL upgrade and special maintenance contracts on the R504 (Wolmaransstad to Leeudoringstad and to Bothaville) offered an opportunity to do upgrades to various streets. A budget of R30 million was set aside for such CDP street upgrade and rehabilitation of selected badly deteriorated streets in these towns. A variety of NME technologies were designed for implementation. The traditional single seal or Cape seal was used as surfacing on the surfaced streets. Cement treated base type construction was also done for comparative purposes as well as gravel preservation treatment of some lower traffic volume streets. There are various lessons learnt by the collective team involving client, consultant and contractor plus community based local contractors as sub-contractors.